System and method for loading and feeding a shotgun

ABSTRACT

A trigger group assembly for a semi-automatic shotgun includes a follower pin that is slideably attached to a sliding track assembly. The follower pin engages a pair of tracks to facilitate cooperation the sliding track assembly&#39;s carrier with the shell retainer of a detachable magazine in such a way that when the bolt is propelled rearward, a cartridge is released from the magazine, and when the bolt is propelled forward, the cartridge is lifted by the carrier into the path of the bolt and loaded into the chamber of the firearm.

RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No.10/907,038, filed on Mar. 17, 2005; which is a continuation-in-part andclaims the benefit of U.S. patent application Ser. No. 10/382,568, nowU.S. Pat. No. 6,877,265, entitled “System and method for increasedmagazine capacity for a Firearm,” filed Mar. 6, 2003; which claims thebenefit of U.S. Provisional Patent Application Ser. No. 60/363,837,entitled “Large Capacity Ammunition Magazine And CooperatingSemi-Automatic Shotgun,” filed Mar. 14, 2002; and, U.S. PatentProvisional Application Ser. No. 60/387,346, entitled “Large CapacityAmmunition Magazine And Cooperating Semi-Automatic Shotgun,” filed Jun.10, 2002. The contents of these applications are incorporated herein byreference.

TECHNICAL FIELD

The present invention relates generally to the field of firearms, andmore particularly, to a system and method for loading and feeding acartridge into the firing chamber of a semi-automatic shotgun.

BACKGROUND OF THE INVENTION

Throughout the history of the firearm, particularly as to an instrumentof warfare and defense, its development has been guided by the purposeof rapidly firing a large amount of projectiles while requiring minimalreloading. The shotgun is one particular firearm that has been aneffective close-range weapon. Although the shotgun has been proveneffective as an entry weapon wherein close-quarters impairs the use oflong-barreled and/or high-powered weapons, its limited ammunitioncapacity, lack of interchangeability among ammunition types, andrelative lengthy reloading time renders today's shotgun less thanadequate in an urban-combat arena.

Various governmental and private security agencies throughout the worldhave expressed a desire for a compact, detachable, magazine-fed shotgunfor tactical operations in close-quarters. Unfortunately, today'ssporting shotguns adapted for law enforcement and military purposesprovide an unsatisfactory option for many tactical situations.

The present invention is provided to address these and other issues.

SUMMARY OF THE INVENTION

The present invention is directed to a method and apparatus for feedingand loading a cartridge from a magazine into the firing chamber of asemi-automatic shotgun having a high capacity magazine including aretainer for retaining cartridges therein. In particular, one embodimentof the present invention includes a trigger group assembly including aslidable track assembly and a trigger frame assembly. The slidable trackassembly includes a feeding track and a loading track and a bolt isslidably coupled thereto. A carrier is pivotally connected to thetrigger frame assembly, and a follower pin is affixed to the carrier andfurther coupled to the feeding track and/or the loading track of theslidable track assembly. During movement of the slidable track assembly,the follower pin travels along the feeding track and/or the loadingtrack and moves the carrier to facilitate the feeding and/or loading ofthe cartridges from the magazine.

In a further aspect of the above embodiment of the present invention, atrigger frame assembly supports the slidable track assembly. Theslidable track assembly includes a means for reducing recoil wherein thebolt in disengaged from and re-engaged to the slidable track assembly.In one preferred embodiment of the means for reducing recoil includes alink is operatively connected to the slidable track assembly andremovably coupled to the bolt. The link is slidably engaged with a railof the trigger frame assembly wherein the link slides off the railduring rearward movement of the slidable track assembly and thusdisengages the bolt from the slidable track assembly until forwardmovement of the bolt, wherein the link slides onto the rail andreengages the bolt to the slidable track assembly.

In a further aspect of the present invention, a trigger group assemblyis operatively coupled to a bolt and a carrier of the semi-automaticshotgun, wherein cartridges are loaded from a high-capacity magazine andfed into a firing position. The trigger group assembly comprises a trackassembly including a feeding track and a loading track—each track havinga first terminus and a second terminus. A pair of deflectors—a first andsecond—each extend from the track assembly proximate its opposing ends.A spool is operatively coupled to the track assembly, wherein duringmovement of the track assembly, the first and second deflectorsfacilitate transition of the spool between the feeding and loadingtracks.

In a further aspect of the present invention, the spool includes a pinhaving a portion that is slideably attached to the shotgun's shellcarrier and alternately engages the feeding and loading of the trackassembly that is further engaged with the moveable bolt of the firearm.The track assembly is capable of cooperating with an actuator and theshell retainer of a detachable magazine in such a way that when the boltis propelled rearward, a shell cartridge is released from the magazine;and when the bolt is propelled forward, the shell cartridge is lifted bythe carrier into the path of the bolt and loaded into the firing chamberof the firearm.

In a still further aspect of one embodiment of the present invention,the actuator carries a spring-biased trip that slides in an inclinedtrack and impinges on the shell retainer of the detachable magazine sothat when the actuator is forced downward by the shell carrier, the tripremains in the path of the emerging cartridge until the cartridge forcesthe trip backward along its inclined track, wherein it disengages fromthe retainer and the retainer can then return to its normal position toblock the release of another cartridge.

An object of the present invention is to provide a semi-automaticshotgun with an alternate configuration for cooperative interactionbetween its shell carrier and bolt.

Another object of the present invention is to provide a semi-automaticshotgun having reduced recoil.

These and other aspects and attributes of the present invention will bediscussed with reference to the following drawings and accompanyingspecification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a high-capacity magazine of the presentinvention;

FIG. 2 is a perspective cross-sectional view of the high-capacitymagazine of the present invention shown in FIG. 1;

FIG. 3 is a partial perspective view of one embodiment of the presentinvention showing the high-capacity magazine and the semi-automaticshotgun;

FIG. 4A is a perspective view of one embodiment of the shell retainer;

FIG. 4B is a view showing the relationship between the shell retainerand the plurality of tubes of one embodiment of the present inventionwhen viewed in line with the longitudinal axis of the magazine;

FIG. 5 is a partial perspective view of one embodiment of the presentinvention showing the high-capacity magazine and the semi-automaticshotgun;

FIG. 6 is a view of one embodiment of the semi-automatic shotgun of thepresent invention;

FIG. 7 is an exploded view of the semi-automatic shotgun shown in FIG.6;

FIG. 8 is a partial cross-sectional view of one embodiment of thepresent invention depicting trigger group assembly including theslidable track assembly and the trigger frame assembly;

FIG. 9 is an alternate embodiment of the semi-automatic shotgun of thepresent invention;

FIG. 10 is a partial perspective view of the high-capacity magazine andcooperating semi-automatic shotgun of an alternative embodiment of thepresent invention;

FIG. 11 is a partial view of one embodiment of the present inventiondirected to a trigger group assembly and including the shell retainerwith which it cooperates;

FIG. 12 is a partial perspective view of one embodiment of a triggergroup assembly of the present invention including a track assemblysupported by the trigger frame assembly;

FIG. 13 is a perspective view of the spool, pin, shell carrier, andactuator assembly of the trigger group assembly of the presentinvention;

FIG. 14 is a perspective view of the spool after the slidable trackassembly has moved rearward along a feeding track of the slidable trackassembly in the course of the feeding cycle of the action system;

FIG. 15 is a perspective view of the spool moving along a loading trackduring forward movement of the track assembly in the course of theloading cycle of the action system;

FIG. 16 is a partial perspective view of the trigger group assemblyafter the spool has reached the terminus of the loading track and beentransitioned to the feeding track;

FIG. 17 is a partial perspective view of the trigger group assemblyduring a portion of the feeding cycle;

FIG. 18 is a partial perspective view of the trigger group assemblyafter the spool has reached the terminus of the feeding track and beentransitioned to the loading track;

FIG. 19 is a partial perspective view of the trigger group assemblyduring a portion of the loading cycle;

FIG. 20 is a partial perspective view of the trigger group assemblyafter the spool has reached the terminus of the loading track and beentransitioned to the feeding track;

FIG. 21 is a partial perspective view of the trigger group assemblyafter the shell cartridge has been fed from the magazine and loaded intothe firing chamber of the semi-automatic shotgun and ready to fire;

FIG. 22 depicts an alternate embodiment of the trigger group assemblyand the cooperating shell retainer with the bolt in the forward, i.e.,in battery, position; and,

FIG. 23 depicts the alternate embodiment of the trigger group assemblyand the cooperating shell retainer shown in FIG. 22 with the bolt in thefurthest rearward position and the slidable track assembly in therearward, i.e., feeding, position.

DETAILED DESCRIPTION

While this invention is susceptible to embodiments in many differentforms, there are shown in the drawings and will herein be described indetail, preferred embodiments of the invention with the understandingthat the present disclosures are to be considered as exemplifications ofthe principles of the invention and are not intended to limit the broadaspects of the invention to the embodiments illustrated.

Referring to the drawings in detail, wherein similar referencecharacters designate corresponding parts throughout the several views,one embodiment of the present invention shown in FIGS. 1 and 2 is ahigh-capacity magazine 1 for holding a cartridge 7 for use with afirearm 54 shown in FIGS. 6-9. The firearm 54 includes an actuator 33operatively connected to a trigger group assembly 65 shown in FIG. 8.The magazine 1 comprises a plurality of tubes 2 being defined within themagazine and axisymmetric about a longitudinal axis 50. Each tube 2 ispreferably cylindrically shaped and includes a first end 51 and a secondend 52—the first end is open. A retainer 6 is mounted about the open end51 of the tubes 2 and is adaptive to impede release of the cartridge 7from the open end of the tube. When the magazine 1 is attached to thefirearm 54, the retainer 6 is operatively meshed with the actuator 33wherein the retainer and the actuator cooperate to permit removal of thecartridge 7 from the magazine.

The magazine 1 further includes a bias 5, e.g., spring, contained withinthe magazine for urging the cartridge 7 toward the open end 51 of thetube 2 wherein the retainer 6, actuator 33, and bias cooperate to expelthe cartridge from the magazine 1 in response to movement of the triggergroup assembly 65 and subsequent motion of the actuator. FIGS. 2 and 8depict the bias 5 contained within each tube 2. The spring 5 is of asufficient rate to effectively expel stored cartridges 7—lethal andnon-lethal—releasably retained within the magazine 1 by the retainer 6.A follower 4 may be utilized between the spring 5 and the cartridge 7.

The retainer 6 further comprises a plurality of leaves 16axisymmetrically aligned with the longitudinal axis 50 of the magazine 1wherein the plurality of leaves impede the release of the cartridges 7from the open ends 51 of the tubes 2. The plurality of leaves 16 may beaffixed about the perimeter of the magazine 1 near the open ends 51 ofthe tubes 2.

Although the retainer 6 as depicted in FIG. 2 is secured along thelongitudinal axis 50 of the magazine 1, it is to be understood thatother means of retaining the cartridge 7 and cooperating with thetriggering assembly action of the firearm to transfer the cartridge fromthe magazine to the firearm 54 may be devised within the scope of theinvention.

Alternatively, the retainer 6 may include a base 60 having alongitudinal axis 53 as shown in FIG. 2. The plurality of leaves 16 areconnected to the base 60, and the base is coaxially aligned with thelongitudinal axis 50 of the magazine 1. Additionally, as shown in FIG.2, a collar 8 can be incorporated to retain the spring 5 and follower 4within the ammunition tube 2. Preferably, the collar 8 includes alongitudinal axis in alignment with the longitudinal axis 50 of themagazine 1 and is secured to the magazine near the open ends 51 of thetubes 2. The collar 8 is of such diameter and design as to impedefurther travel of the follower 4, and spring 5, without impeding thecartridge 7 having a slightly smaller diameter.

Referring to FIGS. 2, 4A, 4B, and 8, the retainer 6 is mounted about theopen end 51 of the tubes 2 and preferably comprises a plurality ofleaves 16. Each leaf 16 is associated with one or more tubes 2. Eachleaf 16 is of sufficient stiffness to maintain its corresponding portion17 in the path of the cartridge 7 against the force of the spring 5.Although a portion 17 of a single leaf 16 may cooperate effectively withmore than one of the tubes 2—and vice versa—it is preferable that anexclusive relationship exists between each one of the plurality of tubes2 and each one of the plurality of leaves 16 wherein a portion 17 of theretainer 6 overlaps an associated portion of one of the plurality oftubes 2 when viewed perpendicularly to a plane normal to thelongitudinal axis 50 of the magazine 1. FIGS. 4A and 4B depict such atube-retainer relationship between each of the plurality of leaves 16and each of the plurality of tubes 2 wherein each portion 17 of the leaf16 is substantially parallel to a plane substantially normal to thelongitudinal axis 51 of the magazine 1. The portion 17 of the leaf 16intersects a circumference 61 of the associated tube 2. The tubecircumference 61 includes the surface of the tube 2 and extends beyondthe ends of the tube.

Referring now to FIGS. 3 and 5-7, the magazine 1 further includes ameans for indexing a selected tube 2 for alignment with the receiver 28of the firearm 54. An index assembly 66 is operatively connected to themagazine 1 and adaptive for rotating the magazine about its longitudinalaxis 50. The index assembly 66 is capable of aligning one of theplurality of tubes 2 when attached to the firearm 54.

Pushing a release button 20 attached to a spring-loaded 21 detent 11releases the magazine 1 from its present position wherein the magazinecan be rotated to index the desired tube 2 in position for injectingammunition 7 into the firearm 54. A number of cartridges 7 can besequentially cycled through the firearm 54 utilizing one tube 2. Betweenfirings, the magazine 1 may be manually advanced at any time to presentanother tube 2, or the magazine may be quickly removed and replaced byanother magazine. Additionally, different types of munitions 7 may beloaded into different tubes 2 in one magazine 1 to allow the firearmoperator to select and index to the desired munitions without having toremove the magazine, which would otherwise render the firearm operatormomentarily “unarmed.” The selectability of tubes 2 provides the firearmoperator with the ability to utilize various types of ammunition, e.g.,lethal, non-lethal. As such, the firearm 54 is adaptive to varioussituations requiring lethal and non-lethal responses without having todisengage the magazine 1 from the firearm.

As an example, one tube 2 can be loaded with teargas canisters, anothertube can be loaded with non-lethal projectiles, e.g., rubber bullets,and another tube can be loaded with lethal ammunition. A situation mayarise wherein an initial non-lethal response is required. After a periodof time, the severity of the situation may escalate wherein use of alethal response may be warranted. The firearm 54 of the presentinvention can be readied for an appropriate response by indexing thetubes 2 so that the lethal ammunition is positioned for feeding into thefirearm. Thus, the firearm operator can quickly adapt to changingsituations by either advancing the magazine 1 to the appropriate tube 2or quickly removing one magazine for another, without having toindividually remove each cartridge 7 from the magazine prior toreloading the magazine with another type of ammunition.

To facilitate adaptation of the magazine 1 and/or firearm to the variouslevels of response, an indicator can be utilized to identify the type ofammunition stored in the magazine and cylinder tube 2. The indicator,e.g., color, letter, marking, shape, or combination thereof; ispreferably located on an outer portion of the magazine 1 or tube 2 foridentification by the firearm user. The user can confirm alignment of adesired ammunition type by inspecting the position of the indicator withrespect to the firearm.

The magazine 1 also includes means for connecting the magazine to thefirearm 54. Referring again to FIGS. 3 and 5-7, a connector assembly 67is affixed about the second end of the magazine 1 and is adaptive forattachment to the firearm 54. The connector assembly 67 preferablyincludes a round boss 3 wherein the magazine 1 can be attached anddetached with the firearm 54. The magazine 1 may be removed from thefirearm 54 by depressing the upper forward surface 49 of the pivot cup9, shown in FIG. 5, and simultaneously pulling down on the end of themagazine 1. In the preferred embodiment, the magazine 1 serves as thefore-end or forward holding surface of the firearm 54. Thus, theoperator's forehand is always in position to index and/or release themagazine 1. In the preferred embodiment of the invention, removal of themagazine 1 can be accomplished with one hand.

As shown in FIGS. 3, 5, and 7, the magazine 1 is attached to the firearm54, e.g., semi-automatic shotgun, by inserting the end of the magazineproximate the open ends of the tubes 2 into a shallow cylindrical well13 that is fixed to, and part of, the firearm receiver 28. The oppositeend of the magazine 1 can be moved upward so that the round boss 3 snapsinto the spring-loaded 21 hinged-cup 9 that pivots on an axle 10 of abracket 12 attached to a forward end of a firearm barrel 15. Themagazine 1 is retained parallel to and below the barrel 15—free torotate around its longitudinal axis 50. The magazine 1 is aligned by theindex assembly 66 wherein the detent 11 snaps into an appropriate socket18 aligned with the one of the plurality of tubes 2 in which the tube isin position to release the cartridge 7 into the firearm 54.

It is to be understood that alternate means of retaining and indexingthe magazine 1 in an operative position using regularly spacedindentures about the longitudinal axis 50 can be easily devised withinthe scope of the present invention.

One embodiment of the firearm's 54 trigger group assembly 65, shellcarrier 37, and receiver 28 are shown in FIG. 8. The trigger groupassembly 65 is operatively meshed with the actuator 33. Pulling of thetrigger 32 momentarily displaces the actuator 33 to dislocate theportion 17 of one of the plurality of leaves 16 being operativelyaligned with the actuator. Ammunition 7 is released by the dislocatedportion 17 of the leaf 16 and transfers into the firearm 54 forsubsequent firing.

Mechanisms for cooperating with a high-capacity magazine 1 and forreleasing, receiving, and maneuvering ammunition into a barrel 15, aswell as the hammer, safety, and firing mechanism, are preferablycontained within a pistol-grip lower receiver 29 and are of relativelyconventional design common to sporting semi-automatic shotguns wellknown to those familiar with firearm design. The magazine 1 isdetachably affixed to the firearm 54, parallel to, and under theshooting barrel 15 wherein a selected one of a plurality of ammunitiontubes 2 can be aligned with a receiver assembly of the firearm.

The preferred embodiment of the present invention shown in FIGS. 5-7 isa gas-operated semi-automatic shotgun 54 having two pistons 22 in bores48 symmetrically arranged parallel to, and in close proximity with, thebarrel 15 and magazine 1. The pistons 22 and bores 48 are of appropriatediameter and stroke to unlock a conventional bolt 25 and propel itrearward in the receiver 28 when a cartridge 7 is fired and a portion ofthe propellant gas is vented from the barrel 15 into the piston bores48. The bolt 25 is then propelled forward by springs 23 on guide rods 24fixed to a buttstock 26—engaging the conventional feed mechanism—andreturned to battery. Preferably, the buttstock 26 and pistol grip arefixed to the receiver 28 by an alignment pin 31 in a hole 30 common toseveral sub-assemblies. It is to be understood that other arrangementsof the basic elements of the firearm 54 and other types of operatingsystems, e.g., inertia, retarded-blowback, etc., common to firearmdesign could be easily devised within the scope of the presentinvention.

The trigger group assembly 65 of the preferred embodiment depicted inFIG. 8 utilizes elements common to semi-automatic shotguns including atrigger 32 that pivots on a first pin 34; a sear 40 and a disconnect 41that pivot on a second pin 45; a hammer 38 and a shell carrier (carrier)37 that pivot on a third pin 39; and a shell carrier pawl 42 that pivotson a fourth pin 43 in the shell carrier 37. The device of the presentinvention comprises a magazine 1 including a retainer 6 being centrallylocated among the plurality of ammunition tubes 2. The retainer 6 ismeshed with an operatively connected actuator 33. The actuator 33 isoperatively connected to the trigger group assembly 65 of the firearm54, e.g., pivotally attached to the first pin 34, wherein the actuator33 and retainer 6 cooperate to allow cartridges to be removed from thetubes 2.

More specifically, a shell carrier latch 36 being pivotable about afifth pin 35 is held in a ready-position by a latch spring 47. When thetrigger 32 is pulled, the shell carrier latch 36 engages and pulls downon the actuator 33, which in turn pulls down on the portion 17 of theretainer 6 and releases a shell cartridge 7 to be propelled rearward bythe spring 5 and follower 4. The released shell impinges on the shellcarrier latch 36 and disengages it from the carrier 37 and the actuator33—thus allowing the retainer portion 17 of the leaf 16 to return backinto position to retain the next shell within the tube 2. As the carrier37 is released, it is caused to rotate about its axis by the shellcarrier pawl 42 that is engaged in a notch 44 in the bolt 25, which isurged forward by the bolt return springs 23. As the carrier 37 rotatesand lifts the shell cartridge 7, the shell carrier pawl 42 disengagesfrom the bolt 25, allowing the bolt to push the shell ahead of it intothe firing chamber. As the forward-moving bolt 25 clears the shellcarrier pawl 42, the shell carrier spring 46 causes the shell carrier 37to rotate back to its original position, re-engaging the shell carrierlatch 36. If there is no shell in position to feed when the trigger 32is pulled, the carrier 37 is not released and the bolt 25 is retained inits rearmost position by the shell retainer pawl 42 after it has beenpropelled backward by the expanding gas of the cartridge 7 just fired.This functionality provides that when the bolt 25 is locked back, thefirearm operator knows the magazine tube 2 is empty and may index to thenext tube in the magazine 1 or load another magazine. Manual means todisengage the shell carrier latch 36 without pulling the trigger 32 canbe easily devised, thus allowing the firearm operator to close the bolt25 on an empty chamber.

FIG. 10 depicts another embodiment of the invention involving thecooperation between the trigger group assembly 65 and the magazine 1.The carrier 37 pivots on pin 77 and impinges directly on the shellretainer 16. The carrier latch 36 is pivotally attached to the carrier37 by pin 35 and engages a cross bar 72 fixed between the longitudinalmembers of a transfer bar 71 that pivots on pin 76. The transfer bar 71has a cam follower portion 73 that is impinged on by an angled surface74 in the bolt 25. When the trigger 32 is pulled, it causes the sear 40to release the hammer 38 that impinges on the firing pin of the bolt 25that fires the shell cartridge 7 in the barrel 15 of the firearm 54. Thegas pressure of the fired shell 7 then forces the bolt 25 rearward, thuscausing the angled surface 74 to force the cam follower portion 73 ofthe transfer bar 71 downward. It is to be understood that in thisembodiment, the bolt is a delayed-blowback roller-lock type well knownto firearm designers, but that other types of actions systems can beutilized. The crossbar 72 in the downward pivoting transfer bar 71 pullsdown on the carrier latch 36 that is pivotally fixed in the carrier 37,causing the carrier to pivot downward and impinge on the retainer 16,releasing the shell 7 from the magazine 1. As the shell 7 is propelledout of the magazine, it strikes the carrier latch 36, causing it topivot on pin 35 and disengage from the crossbar 72 in the transfer bar71; this then allows the shell carrier 37 to lift the shell up and infront of the returning bolt 25, which has momentarily engaged thecarrier pawl 42 to force the carrier 37 to pivot upwards on pin 77. Asthe returning bolt 25 forces the shell 7 into battery in the barrel 15,its forward surface 78 impinges on the carrier 37 and impels it downwardso the carrier latch 36 is re-engaged with the crossbar 72.

In short, the rearward movement of the bolt 25 causes the shell 7 tofeed from the magazine 1, and the emerging shell trips the carrier latch36 to release the retainer 16 back to its normal position to stop thenext shell. If there are no more shells 7 in the magazine tube 2 to bereleased, the carrier latch 36 will not be disengaged from the crossbar72 in the transfer bar 71 and the carrier 37 will not be allowed topivot upwards when the returning bolt 25 engages the carrier pawl 42,thus retaining the returning bolt 25 in the “locked-back” position. Anotch 75 is provided in the bolt 25 to allow the cam follower portion 73of the transfer bar 71 to rotate upwards, thus allowing the carrier 37to release its pressure on the retainer 16 so that the magazine 1 may beindexed to another tube 2 or removed and replaced. After the magazine 1is indexed or replaced, the transfer bar 71 may then be depressed by amanual means available to the operator, thereby releasing a shell 7 fromthe magazine tube 2, which upon tripping the carrier latch 36 allows thecarrier 37 to lift the shell and release the bolt 25 to carry the shell7 into battery ready to fire.

FIG. 9 depicts an alternate configuration wherein the magazine 1 may beinserted into a cylindrical well 70 of a shotgun with suitable means toremovably retain the magazine and engage the regular indentures aboutits circumference for indexing purposes. In such a case, the element ofthe cooperating action of the firearm can be suitably reconfigured.

The preferred embodiment of the present invention incorporates certaindesign features specifically directed toward tactical operations by lawenforcement and military personnel operating in close-quarters such asapartment buildings and aboard ships. Several desired characteristics ofthe firearm include automatic or semi-automatic firing action; a shortoverall length; lightweight; minimal snagging protuberances; andcorrosion-resistant materials—suitable for close-quarter tacticalsituations. The firearm 54 is also capable of incorporating an accessorymounting rail 19 integral to the receiver 28 consistent with mil-spec1911 for attaching aiming and illuminating devices (not shown).

The firearm 54 is preferably designed for ease and relative low cost ofmanufacture—utilizing molded, machined, or fabricated plastic materialfor the magazine 1, pistol-grip lower receiver, and buttstock; metaldie-stamping for the receiver and action parts; investment casting forthe trunnion block 14, and bolt parts to minimize expensive machiningoperations.

The size of the firearm 54 and the number of ammunition tubes 2incorporated within the magazine 1 is dependent upon the firearmmanufacturer's preference. In one embodiment, the dimensions of thefirearm include an overall length of 28 in., a height of 7 in., and afully loaded weight of approximately 9 pounds. It may be preferable toutilize a magazine 1 having four cylindrical tubes 2, as five may be toolarge to securely and comfortably grasp for the average hand, whilethree tubes may require a greater degree of rotation between indexedtubes. Each tube 2 can hold four shot shells, e.g., 2¾ in., 12 gauge;for a total of sixteen rounds per magazine 1. It is also to beunderstood that other configurations having more or less capacity andlarger or smaller munitions could easily be devised within the scope ofthe invention.

FIGS. 11-16 depict another embodiment of the present invention directedto a trigger group assembly 65 for a shoulder-fired firearm capable ofproviding a positive method for positioning the carrier 37 relative tothe bolt 25; as opposed to utilizing a spring-loaded pawl commonlyincorporated in semi-automatic shotguns. In particular, a slidable trackassembly 93 acts on the carrier 37 and the actuator assembly 33 to feedand load cartridges of ammunition from the magazine 1 to the firingchamber of the shotgun. This embodiment of the track assembly 93 iscapable of cooperating with the high-capacity magazine described in U.S.Pat. No. 6,877,265. It is to be understood that the trigger groupassembly 65 of the present invention is capable of being adapted forcooperation with other embodiments of actuators 33 that are also capableof meshing with other types of retainers 6 of other cartridge magazines1.

The trigger group assembly 65 includes the sliding track assembly 93that is coupled to—and propelled by—the bolt 25, and which cooperateswith the carrier 37 to act on the actuator 33 to feed and loadcartridges of ammunition from the magazine 1 to the firing chamber ofthe shotgun. As seen in FIGS. 11-14, the carrier 37 is pivotally 77attached to a trigger group frame 98. A spool 91 is attached to thecarrier 37 preferably by a follower pin 84. The follower pin 84 isslidable and attached to the carrier 37 near its end, wherein a portion92 of the pin is capable of traveling within the track assembly 93, inparticular, a feeding track 94 and a loading track 95. The spool 91 iscapable of traveling along either track 94, 95 such that when the spool91 is slid along the axial pin 84 to its limit near one side of thecarrier 37, the portion 92 of the pin 84 protrudes beyond the carrierinto the feeding 94 or loading 95 track of the track assembly 93, butdoes not protrude beyond the carrier on the opposite side. That is, thepin 84, or the portion 92 thereof, can travel in either the feeding 94or loading 95 track, but not simultaneously in both tracks—except forperhaps a brief movement of transition of the spool 91 there between, ateither terminus of the tracks. The sideways—axial—movement of the spool91 and pin 84 from one track to the other is accomplished by a first 96and second 97 deflectors, or ramps extending from the track assembly 93shown in FIGS. 15 and 16.

When the shotgun is fired, the bolt 25 begins to move rearward, takingthe engaged slidable track assembly 93 along with it. When the portion92 of the pin 84 encounters the incline in the feeding track 94, thepivotally mounted carrier 37 slightly rotates about its axis 77 andforces a front edge of the carrier down on the actuator assembly 33,which rotates in turn about its axle 82 and forces its sliding trip 80(see FIGS. 13 and 17) down on the top leaf 17 of the retainer 6 in themagazine 1, thus releasing a cartridge 7 that is urged rearward by thespring 5.

When the released cartridge 7 encounters the sliding trip 80 in itspath, it pushes it backward in an inclined track in the actuator 33against a spring-loaded plunger 81 until the trip 80 is disengaged fromthe retainer 6 and submerged beneath the path of the cartridge, thusallowing the top leaf 17 of the retainer 6 to return to its normalposition and block the next-in-line cartridge from exiting the magazine1.

As the bolt 25 and track assembly 93 approach their rearward terminus,the first deflector 96 transitions the spool 91 over so that the portion92 of the pin 84 vacates the feeding track 94 and engages the loadingtrack 95 of the track assembly 93. (See FIG. 18). Then, as the bolt 25and track assembly 93 are urged forward by the firearm's return spring23, the portion 92 of the pin 84 is forced downward by the loading track95, which rotates the carrier 37 upwards, lifting the cartridge upwardsinto the path of the bolt 25, which loads the cartridge into the firingchamber of the shotgun. (See FIG. 19). When the bolt 25 and trackassembly 93 approach their forward terminus (e.g., in battery), thesecond deflector 97 transitions the spool 91 over so the portion 92 ofthe pin 84 is re-engaged in the feeding track 94 of the track assembly93 (see FIG. 20), and now ready to feed a new cartridge when thecartridge in the chamber is fired (see FIG. 21).

During operation of the shotgun of the present invention describedabove, it was observed that upon firing, the shotgun and the attachedhigh capacity magazine 1 recoiled immediately, but the inertia of theshell(s) 7 within the high capacity magazine delayed the shell's exitfrom the magazine until the bolt 25 was already fully rearward. Inresponse to the cartridge's delayed exit, the path of the track(s) 94,95 in the sliding track assembly 73 was altered so that the follower pin84 having a portion 92 traveling within the feeding track 94 would notfacilitate rotation of the carrier 37 downward to depress the shellretainer 6 and release the cartridge until the bolt 25 had driven thesliding track assembly 93 to its rearward terminus. In addition, alink(s) 86 was included and configured to timely slide off of thesupporting rail(s) 87 of the trigger frame assembly 98, thus disengagingthe bolt 25 from the slidable track assembly 93 as shown in FIGS. 22 and23. This configuration provides more time to allow the shell 7 to exitthe high-capacity magazine 1, and further allows the sliding trackassembly 93 to come to a smoother stop without a significant terminalimpact, which thus allows the bolt 25 to continue rearward against theresistance of the recoil/return springs 23 until the bolt is stoppedmore smoothly with minimal impact. It is to be understood that althoughvarious trigger assemblies are capable of being utilized with thesliding track assembly 93 of the present invention, FIGS. 22 and 23depict a preferred embodiment of the sliding track assembly that iscapable of cooperating with the actuator 33 to mesh with the retainer 6of the high capacity ammunition magazine 1—in particular, the retainerand high capacity magazine described herein, as well as in U.S. Pat. No.6,877,265.

The sliding track assembly 93, which is slidably attached to andpropelled by the bolt 25, acts on the carrier 37, which acts on actuator33 to feed and load rounds 7 of ammunition from the magazine 1 to thefiring chamber of the shotgun. In particular, the sliding track assembly93 is releasably engaged with the bolt 25, and is further slidablyaligned with the trigger frame assembly 98. The sliding track assembly93 also includes a track 90 capable of receiving the follower pin 84 ofthe carrier 37. The follower pin 84 travels within the track 90 whilethe carrier 37 moves, i.e., pivots, within the trigger group assembly65. Preferably, two tracks are utilized as in the earlier describedembodiment of the sliding track assembly 93, however unlike the earlierembodiment that includes differently shaped tracks for loading andfeeding, the sliding track assembly 93 shown in FIGS. 22 and 23 includeidentical opposing tracks 90 mirroring each other, wherein the followerpin 84 simultaneously engages both tracks 90 (feeding and loading) anddoes not shuttle from one track to the other track.

In addition, the sliding track assembly 93 depicted in FIGS. 22 and 23was modified to include a link 86, preferably a pair of links, pivotallyattached to the sliding track assembly 93 by an axle 85 and which arecapable of removably engaging the rear surface of the bolt 25 when thelinks are supported by the rails 87 of the trigger frame assembly 98.Thus, the movable links 86 are capable of disengaging and reengaging thebolt 25 to the sliding track assembly 93. That is, as the bolt 25travels rearward, the links 86 disengage from the bolt 25 as the linksslide off the rails 87 and are not supported. The bolt 25 continuessliding rearward against the return/recoil spring(s) until it stops. Asthe return/recoil spring(s) 23 drives the bolt 25 forward, the frontsurface of the bolt impinges on the boss(es) 79 of the sliding trackassembly 93, in turn driving the sliding track assembly forward, whichthen causes the hinged links 86 to ride-up on the rails 87 of thetrigger frame assembly 98 and reengaging the bolt 25 with the slidingtrack assembly, and which causes the follower pin 84 to rotate thecarrier 37 upwards, lofting the shell into the forward path of the boltwhich then, as it comes into battery, loads the shell into the firingchamber of the semi-automatic shotgun that is now ready for anothercycle. This preferred embodiment of the trigger group assembly 65provides for the symmetric support of the follower pin 84 when it isunder load, i.e., during pressing of the retainer 6 and lofting of theshell. It further accommodates for the inertial delay of the shell(s)within the high-capacity magazine 1 and also simplifies the mechanism byeliminating the spool 71 and the first 96 and second 97 deflectors whilealso reducing the recoil of the bolt 25 “bottoming out” by allowing thebolt to disengage from the sliding track assembly 93—which must stop ata certain terminus—when the links 86 ride off of the rails 87 of thetrigger frame assembly 98 and continue to compress the recoil spring(s)23 until the bolt comes to a relatively smoother stop with minimalimpact before it is returned forward.

Each of the embodiments of the sliding track assembly 93 as seen inFIGS. 11, 12, 14, 22, and 23 may also include an actuator lever 83 thatcan be attached to an actuator axle 82 to provide an externallyaccessible means by which the operator can manually feed a cartridgefrom the magazine 1.

It will be understood that the present invention may be embodied inother specific forms without departing from the spirit or centralcharacteristics thereof. The present embodiments, therefore, are to beconsidered in all respects as illustrative and not restrictive, and theinvention is not to be limited to the details given herein. Whilespecific embodiments have been illustrated and described, numerousmodifications come to mind without significantly departing from thecharacteristics of the invention and the scope of protection is onlylimited by the scope of the accompanying Claims.

1. A trigger group assembly for a semi-automatic shotgun having ahigh-capacity magazine including a retainer for retaining cartridgestherein, the trigger group assembly comprising: a follower pinoperatively connected to a carrier, wherein the follower pin is capableof engaging a feeding track and a loading track of a slidable trackassembly, the slidable track assembly being operatively connected to abolt of the shotgun, wherein the carrier cooperates with an actuator andthe retainer of shotgun's magazine, the actuator being responsive tomovement of the carrier in such a way that when the bolt is propelledrearward, the cartridge is released from the magazine and when the boltis propelled forward, the cartridge is lifted by the carrier into thepath of the bolt and loaded into the chamber of the shotgun.
 2. Thetrigger group assembly of claim 1 wherein the feeding track is in afirst plane and the loading track is in a second plane, and the firstand second planes are substantially parallel.
 3. The trigger groupassembly of claim 1 wherein the actuator includes a spring-biased tripthat slides in an inclined track and impinges on the retainer of themagazine such that when the actuator is forced downward by the carrier,the trip remains in the path of the emerging cartridge until thecartridge forces the trip backward along its inclined track such that itdisengages from the retainer, wherein the retainer returns to its normalposition to block the release of another cartridge.
 4. The slidabletrack assembly of claim 1, wherein the feeding track and the loadingtrack each having a first terminus and a second terminus; the slidabletrack assembly further comprising: a first deflector extending from theslidable track assembly proximate a first end of the slidable trackassembly; and, a second deflector extending from the slidable trackassembly proximate a second end of the slidable track assembly, whereinduring movement of the slidable track assembly, the first and seconddeflectors facilitate coupling transition of the follower pin betweenthe feeding and loading tracks.
 5. The trigger group assembly of claim 1further comprising: a trigger frame assembly supporting the slidablytrack assembly, the carrier being pivotally attached to the triggerframe assembly; and, a spool operatively connected to the follower pin,wherein movement of the spool in response to engagement between thefollower pin with the feeding and loading tracks results in a feedingand loading cycle of the carrier, respectively.
 6. The trigger groupassembly of claim 1 further comprising: a lever operatively connected tothe actuator, the lever being accessible external to the semi-automaticshotgun and capable of being manually operated, wherein manual actuationof the lever facilitates release of a cartridge from the magazine. 7.The trigger group assembly of claim 1 further comprising: a triggerframe assembly supporting the slidable track assembly, the trigger frameassembly including a rail; and, a means for reducing recoil.
 8. Thetrigger group assembly of claim 7 wherein the means for reducing recoilcomprises: a link operatively connected to the slidable track assemblyand removably engaged to the bolt, the link being capable of slidingalong the rail of the trigger frame assembly wherein as the link slidesoff the rail during rearward movement of the slidable track assembly,the bolt disengages from the slidable track assembly until forwardmovement of the bolt whereupon the link slides back onto the rail andreengages the bolt to the slidable track assembly.
 9. A semi-automaticshotgun having a high capacity magazine including a retainer forretaining cartridges therein, the semi-automatic shotgun comprising: atrigger group assembly including a slidable track assembly and a triggerframe assembly; a bolt slidably coupled to the slidable track assembly,the slidable track assembly including a feeding track and a loadingtrack; a carrier pivotally connected to the trigger frame assembly; and,a follower pin affixed to the carrier and capable of beingtransitionally coupled between the feeding track and the loading trackof the slidable track assembly, wherein during movement of the slidabletrack assembly, the follower pin travels along the feeding track and/orthe loading track and moves the carrier to facilitate the feeding and/orloading of the cartridges from the magazine.
 10. The trigger groupassembly of claim 9 further comprising an actuator responsive tomovement of the carrier and capable of engaging the retainer of thehigh-capacity magazine.
 11. The trigger group assembly of claim 10wherein the actuator includes a spring-biased trip that slides in aninclined track and impinges on the retainer of the magazine such thatwhen the actuator is forced downward by the carrier, the trip remains inthe path of the emerging cartridge until the cartridge forces the tripbackward along its inclined track such that it disengages from theretainer, wherein the retainer returns to its normal position to blockthe release of another cartridge.
 12. The trigger group assembly ofclaim 10, further comprising a lever operatively connected to theactuator, the lever being accessible external to the semi-automaticshotgun and capable of being manually operated, wherein manual actuationof the lever facilitates release of a cartridge from the magazine. 13.The trigger group assembly of claim 9, further comprising: the triggerframe assembly including a rail; and, a means for reducing recoil. 14.The trigger group assembly of claim 13 wherein the means for reducingrecoil comprises: a link operatively connected to the slidable trackassembly and removably engaged to the bolt, the link being capable ofsliding along the rail of the trigger frame assembly wherein as the linkslides off the rail during rearward movement of the slidable trackassembly, the bolt disengages from the slidable track assembly untilforward movement of the bolt whereupon the link slides back onto therail and reengages the bolt to the slidable track assembly.
 15. Theslidable track assembly of claim 9, wherein the feeding track and theloading track each include a first terminus and a second terminus, theslidable track assembly further including: a first deflector extendingfrom the slidable track assembly proximate a first end of the slidabletrack assembly; and, a second deflector extending from the slidabletrack assembly proximate a second end of the slidable track assembly,wherein during movement of the slidable track assembly, the first andsecond deflectors facilitate coupling transition of the follower pinbetween the feeding and loading tracks.
 16. For a semi-automatic shotgunincluding a trigger group assembly and a high-capacity magazine, amethod comprising the steps of: utilizing the force of a fired cartridgeto move a slidable track assembly in a loading direction, the slidabletrack assembly including a feeding track and a loading track; utilizingthe loading track to move a carrier in a loading cycle; and, utilizingthe feeding track to move the carrier in a feeding cycle.
 17. The methodof claim 16, further including the step of providing a means forreducing recoil.
 18. The method of claim 17, further including:disengaging the shotgun's bolt with slidable track assembly; and,reengaging the shotgun's bolt with the slidable track assembly.
 19. Themethod of claim 18 wherein the means for reducing recoil comprises: alink operatively connected to the slidable track assembly and removablyengaged to the bolt, the link being capable of sliding along the rail ofthe trigger frame assembly wherein as the link slides off the railduring rearward movement of the slidable track assembly, the boltdisengages from the slidable track assembly until forward movement ofthe bolt whereupon the link slides back onto the rail and reengages thebolt to the slidable track assembly.
 20. The method of claim 16 furtherincluding the step of transitioning the carrier from the loading trackto the feeding track.
 21. The method of claim 16, further including thestep of releasing a cartridge from a magazine.
 22. The method of claim21, further including the step of: providing an actuator coupled betweenthe trigger frame assembly and the high-capacity magazine, the actuatorbeing responsive to movement of the carrier, wherein the actuatorcooperates with the high-capacity magazine to facilitate release of thecartridges from the high-capacity magazine.
 23. The method of claim 21,further including the step of: providing a lever, the lever beingconnected to an actuator and further being accessible external to thesemi-automatic shotgun and capable of being manually operated tofacilitate release of the cartridges from the high-capacity magazine.